This invention relates to grouting apparatus and a method for grouting bore holes.
During drilling, for example during exploratory core drilling, caving of earth formations can cause high torque and drill string vibrations problems which result in slower progress in completing the drilling operation. Also, during drilling operations, at times undesirable leakage problems may be encountered.
U.S. Pat. No. 3,175,628 to Dellinger is directed to discharging drilling additives in a bore hole and in particular, flocculating agents. The apparatus includes a sub connected in a drill string above the bit and has a shoulder against which a wire line container may be lowered to abut. A piston in the container is forced under fluid pressure to force the additive out through the orifice at the container lower end. A ring is biased by a spring to a sealing position to block the orifice until the container is adjacent to the above mentioned shoulder.
U.S. Pat. No. 3,027,943 to Reistle, Jr discloses an assembly lowerable by a wire line to have its shoulder seat on the shoulder of a sleeve and to extend though the sleeve. The assembly has a chamber in which a piston, in moving toward the bit end, forces the liquid treating reagent out of the chamber. Fluid for forcing the piston to move in the above manner may be introduced through the outer end of the assembly, for example see FIG. 3. This patent also discloses a packing feature.
U.S. Pat. No. 3,448,800 to Parker et al discloses positioning a plug for separating two fluids that are to be sequentially ejected into the bottom of a bore hole for forming a composition to inhibit lost circulation.
U.S. Pat. No. 3,097,698 to Corley, Jr. et al discloses a wire line cementing tool wherein there is provided a collar stop which apparently limits the inward movement of the tool in the drill string. Ports are provided in the cap member (overshot coupling member) through which hydraulic pressurized fluid can be exerted on the cement in the tool to force the fluid cement out of the tool.
In order to make improvements in grouting apparatus and a grouting method utilized in bore holes, this invention has been made.
A grouting assembly having grouting material therein is movable in a drill string to the inner end portion thereof to seat on the drill string landing shoulder and have the assembly nozzle extend inwardly of the drill bit. The assembly has an outer end closure that has an inlet port and an overshot coupling portion adapted to be engaged by a conventional wire line overshot assembly for being lowered or retracted in a drill string. The outer end closure is removably connected to a tubular body while the inner end of the tubular body is removably connected to a discharge nozzle.
The outer end closure, the tubular body and nozzle cooperatively provide a container for having grouting material dispensed thereinto. A piston is provided in the tubular body and it is extended into a sleeve which blocks a piston inlet port as the piston and sleeve are forced inwardly in the tubular body by fluid under pressure. Upon the piston moving to the inner end of the tubular body, a fluid channel is opened to permit fluid to flow inwardly through the outer end closure inlet and through the piston to be discharged through the nozzle. As a result, after the contents of the container has been discharged, an appropriate fluid under pressure can enter into and flow through the container to react with the contents of the container that were forced out by the piston moving inwardly and then harden.
One of the objects of the invention is to provide new and novel means movable in a drill string for containing a grouting material and discharging said material adjacent to the drill string bit end and permitting the flow of a fluid to mix with the discharged grouting material. Another object of this invention is to provide a grouting assembly having new and novel means for containing grouting material and once the material is discharged at the bit end of the drill string, open a fluid channel to allow fluid from outwardly of the assembly flowing through the assembly to mix with the discharged grouting material.
A different object of the invention is to provide in a retractable grouting assembly that is seatable on a drill string landing shoulder, new and novel means axially movable inwardly under fluid (hydraulic) pressure for forcing grouting material out of the assembly chamber and after the grouting material is forced out of the assembly chamber, allow fluid from exterior of the chamber to flow through the chamber to mix with the grouting material. Still another object of the invention is to provide new and novel means movable axially inwardly in a drill string and retractable through a drill string for facilitating sequentially applying two compositions of a binary grouting system in a bore hole.
For purposes of facilitating the description of the invention, the term xe2x80x9cinnerxe2x80x9d refers to that portion of the drill string, or of the assembly, or an element of the assembly being described when, in its position xe2x80x9cfor usexe2x80x9d in, or on, the drill string is located closer to the drill bit on the drill string (or bottom of the hole being drilled) than any other portion of the apparatus being described, except where the term clearly refers to a transverse circumferential, direction, or diameter of the drill string or other apparatus being described. The term xe2x80x9couterxe2x80x9d refers to that portion of the drill string, or of the assembly, or an element of the assembly being described when, in its position xe2x80x9cfor usexe2x80x9d in, or on, the drill string is located axially more remote from the drill bit on the drill string (or bottom of the hole being drilled) than any other portion of the apparatus being described, except where the term clearly refers to a transverse circumferential, direction, or diameter of the drill string or other apparatus being described.